Elevator



Au 9, 1932. g, AVI 1,8713%? ELEVATOR Filed Jan. 50. 1930 INVENTOR W/Y/iarh 1?. .Da W151 ATTORNEY Patented Aug. 9, 1932 UNITED SlTi-A'TES OFFICE WILLIAM R. DAVIS, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIGKE JVIANUIEACTURING COMPANY, AGORPORATION -.OFPENNS=YLVANIA..N

ELEVATOR Application filed January 30, 1930;. Serial"No.424;545r

My invention-relates to elevators and has particular relationto elevators of the doubleend platform type, in which doors and gates are provided on more than one side of the elevator shaft, sothat the car 'or platform may be loaded from one side of the elevator shaft and unloaded from anotherside. At some landings, two sets of doors and gates may be provided.

If the load on the car is not distributed evenly,'the platform or floorof the car may be tilted slightly so that,'if the platform'is brought to floor level at one door, it may not be level-withthe floor at the other door. In freight elevators, particularly, it is'desirable to hold the platform level with the floor at the door which is opened, assuming that only one door is opened, so thattrucks'of various kinds may be loaded and unloaded with facil- 'ity." If more than one door is opened, it is desirableto have the'platform leveled at the door-which is first opened so that'subsequent opening of the other door will 'not disturb the position of the car." 7

1 It is, accordingly, an object of my invention to provide an elevator system having means for holding the platform level with theflo'or at the door or gate which first opens;

Morespecifically stated, itis'an object of my invention to provide an elevator system,

a plurality of sets of anti-creeping switches,

one set for each sid'eof'the elevator platform which is provided witha gate, and means for controlling. the car by the set of switches cor responding to the side of the platform at which a door orgate first opens-to the excluw sion of the other set or sets.

Other objects of my invention will become evident from the following detailed description; taken in conjunction with the. accom" panying drawing, in which the single figure is a diagrammaticfview of an elevator-control system organized in accordance w th the presture M connected-in a closed circuit with the vided to engage a brake Bd, mounted on the plates, it will be understood that a set is.

closed and remain closed when its coil is.en-'

armature G of a direct-current generator G5 The generator G is -driven by any suitable means. An exciter E for supplying the direct 7 current used in the control system ismounte'd i on the same shaft'as the generator'G'. "Sup-F 5521' ply lines L and L are connected to the eX-i citer'terminals to be energized therefrom.

A spring-pressed, electromagnetically :re-I leased brake'B,'of the usual type'is promotor shaft.

The motor M is provided with a separately excited field winding MF connectedbetween I the supply lines L and Lg. The generator G is provided witha separately excited field winding GF to be-connected to the supply I lines L and L in series with resistorsr' and 1' by means of either of a pair of reversing switchesl and 2. An acceleratingrelay 3, operated from a car switch Gs, is provided for excluding the resistor 'r', toincrease the excitation of'the generator Gr, thereby increas-' ing the speed of motor M. vA pair of inter-' lock relays 4 and 5," operated from thex'car switch .Cs, is.provided for operating the re versing switches 1 and 2 and also for interlocking them so that only one reversing switch car at a landing. While, for simplicity, I

have shown only a single set of inductor provided for. each floor intermediate the top and bottom fiobrs'and that a set correspond- .bottom' floor; An inductor relay, such'as shown diagrammatically at 6,7 or 8, is so designed that its contact members are normally ergized until the relay arrives at a position adjacent to an inductor plate. When this occurs, the relay contact members open, re-' main'ing open until the coil is deenergized, atv

which' timegthe-contact 'members'of therelay close, whether the relay is adjacent to an inductor plate or not.

The elevator system, so far described, is of the automatic-landing type in which movement of the car is initiated by operationof the car switch and in which slowing down and stopping of the car are effected automatically. Such a system is disclosed in the co-pending application of Edgar M. Bouton, Serial No. 731,921., filed August 14L, 1924 and assigned to the Westinghouse Electric & Manufacturing Company.

A pushbutton PB is provided for opening the reversing-switch holding circuits so that the system may be operated manually, if desired.

-A set of canroperated electromagnetically retracted anti-creeping switches LU and L1) is mounted on the car for maintaining the car platform level with the floor at its left end, and a similar set EU and RD is pro-.

vided for maintaining the car platform level at its right end. It will be understood that these switches operate on the circuits of the main motor and that they are so interlocked.

that only one set can be in use at a time, as will be hereinafter more fully set forth. Each of the switches LU, LD, RU and ED is provided with a retiring magnet 9 and an armature 11 carrying a roller 10 and a moving contact member 13 for bridging the contact members 12. When the retiring magnets 9 are energized, thearmatures 11 are attracted to such position that the contact members 12 are bridged by contact member 13, and the rollers 10 are withdrawn from a position in whichtheycould engage cams'LC and BC in the hatchway. When the retiring magnets are deenergized, the rollers 10 drop out into a position to engage the cams LC or RC.

A cam LC or RC is provided for each elevator door in the hatchway. he retiring magnets 9 of the anti-creeping switches LU and LD are connected in parallel to be controlled by normally open contact members a of a relay 39L, and the retiring magnets 9 of the anti-creeping switches EU and R1) are connected in parallel to be controlled by normallyopen contact members a of a relay 393. The relays 39L and 39B also carry norma. ly closed contact members 5 which interlock the relays so that only one relay may be open at a time, and normally open contact members a are connected in series with the operating coil of a relay 38.

Door and gate contact members LP and LG for the left side of the car and elevator shaft are connected in series relation, the circuit of these contact members being connected in parallel with the contact members 5 of relay 39R. Door and gate contact members RP and HG for the right side of the car and el vator shaft are connected in series relation, the clrcuit of these contact members being for the lip-direction switch 1.

connected in parallel with the contact members Z9 of the relay 39R.

A sequence relay SR is provided for preventin the starting of the car by closure of the gates and doors until the car switch Cs has been centered and afterwards moved to a starting position.

A. relay 38 is provided for interlocking the car-switch control circuits and the anti-creeping switch control circuits so that the motor cannot be controlled by the anti-creeping switches while it is being controlled by the car switch and cannot be controlled by the car switch until the anti-creeping control circuits are opened.

The operation of the above-described system may he set forth as follows: The control switches are shown in the position they assume with the car standing at a particular landing, for example, the first with the left end of the car platform level with the floor (desigr ated by reference character FL) and the left gate open.

The circuit of the operating coil of relay 39L has been opened by the opening of left gate contact members LG. This circuit may he traced from line conductor L through conductor 14, the coil of relay 39L, conductor 15, open contact members LG and closed contact members LP, through conductor 16, to line L Relay 39B is energized by a circuit which extends from line L through conductor 14, the operating coil of relay 39R, whence a branch circuit extends, by way of conductor 17, normally closed contact members 5 of relay 39L and conductor 18 to line conductor la while another branch extends through conductor 19, ClOSGC gate and door contact members I i-G and RP and conductor 16, to line conductor L If the car sinks slightly below the floor level for any reason, such, for example, as stretchof the cable as the car becomes loaded, the roller 10 of the anti-creeping switch LU i operated by the cam LC to close a circuit This circuit extends from line conductor L through con ductor 20, contact members 13 and 12 of the anti-creeping switches LU and RU in series relation, through contact members a of the relay 88, through contact members a of the interlocking relay 5, through the operating coil of updirection switch 1 and through the safety devices, to line conductor L The lip-direction switch 1 closes, connecting the generator separately excited field winding G]? to the source of power in series with resistors 2 and T The circuit of the generator field winding extends from line conductor L through conductor 21, resistors r and 1",, conalsocompleted for the release. :coil of the 1 bI'ELkG'JB; This circuit extendsfrom line con-w ductor L ,-through conductor 22, the release coil of brakeB, contact members 0 of up-direction switch 1 to line conductor L The brakeB is released and the generator Gr gen-. erates a low voltage, causing the motor M to rotate atlow speed, moving the cariupward until the roller 10 of anti-creeping switch LU L through conductor 23, contact members 12 and 13 of switch LD, contact members 12' and 13 of switch RD, contact members I) of relay 38, contact members a of interlock relay 4, the operating coil of down-direction switch 2 and, thence, through the safety devices, to line conductor L The car now moves downward :until the anti-creeping switch LD breaksthe circuit of down-direction switch 2,. causing the generator to be deenergized and the brake applied, bringing the car to rest.

If a right gate or door is opened (the left gate being already open) the control of the car is not removed from the left anti-creeping switches LU and LD, as the circuit of relay 39B is maintained through normally closed contact members I) of relay 89L. This circuit may be traced from line conductor L through conductor 14, the energizing coil of relay 39R, conductor 17 and normally closed contact members 6 of relay 39L, to line conductor L If it is desired to bring the right end of the elevator platform level with the floor, the

left gates and doors must all be closed, and a right gate or dooropened. Upon closure of the left gate, an energizing circuit for relay 39L is completed as'follows from line conductor L through conductor 14, the operating coil of relay 39L, left-gate contact members LG and left-door contact members LP, to line conductor L Relay 39L closes, establishing a circuit for the retiring coils 9 of the left anti-creeping switches LU and LD. This circuit extends from line conductor'L through the coilsf9 of switches LU and LD in parallel and through contact members a of relay 39L, to line conductor L Closure of relay 39L also prepares the circuit of-relay 39R for subsequent opening when a right door or gate is opened, by the opening of its normally closed contact members 7),

' which :contact members are in parallel relasequence relay SR, contact members 0 of relay 39L and contact members 0 of relay 39R and. conductor 18, to line conductor L Relay .38 closes, opening its contact members a and '6, thus preventing control of directionswitches l and 2 by any of the anticreeping switches LU, LD, EU or RDand. closing its contact members (Z preparing the motor circuit for control by the car switchi Csyas will hereinafter be more fully ex plained.

If: a right door or gate is now-opened, the circuit of relay 39B is interrupted, the relay S9R.drops:out, breaking the circuit of relay 38 at contact members 0 of relay 39R, brealo ing the circuit of retiring magnets 9 of anti creeping switches RU and-RD'at: contact members a of relay 39R and closure of contact members I) of relay 39R to establish a circuit-for relay 39L which parallels'the nor- -mal circuit for relay 39L (thenormal circuit leading through door and gate contact members LP and LG) so that subsequent opening of a left door or gate will not cause relay 39L to drop out. Relay 38 dropsout to prepare the circuits of the direction 1 switches -1 and 2 for control by the anticreeping switches RU and RD by closure of contact members a and b of relay 38." The retiring 'magnets' of anti-creeping switches EU and RD, being deenergized, the rollers 10 of these switches drop out into engagement with the cam EC to maintain the right end of the platform level with the floor, in the manner described for the'left end.

If theright doors and gates are now closed, (the left doors and gates being already closed) an energizing circuit for relay 39B is established as follows: from line conductor L through conductor 14, through'the operating coil of relay 39R, gate contact members RG and door contact members RP, to line conductor'L The relay 39R closes its contact members 0 to re-establish the circuit of relay 38; Relay 39R also closes its contact mem- 'bersa to reestablish the circuit of retiring magnets 9 of switches RU and RD. Relay 393 also opens its contact members 6 to prepare the-circuit of relay 39L for subsequent control by door and gate contact members. Anti creeping switches EU and RD are re tired from engagement with the cam RC, and relay 38 closes. The opening of contact members a and Z) of relay 38 prevents control of the reversing switches 1 and 2 by any of the anti-creeping switches LU, Ll), RU or RD, and contact members (Z of relay 38 prepare the circuits of reversing switches 1 and 2 for control by the car switch C3.

doors and gates are closed, the relays 38, 39L and 39B are all energized, the anti-creeping switches LU, LD, EU and RD are all retired, the car switch Cs is centered, andthereversing switches 1 and 2, acceleratin relay 3 and interlock relays 4 and 5 are all deenergized.

Operation of the car in either direct-ion can now be initiated by the car switch. Let us assume that it is desired to operate the car upward to the third floor. The operator moves the handle of the car switch Us in a counter-clockwise direction to cause the car switch segment to engage contact members 26 and 27. This operation completes a circuit for interlock relay 4 as follows: from line conductor L through conductor 24, contact member 26, contact segment 25 and contact member 27 on car switch Cs, conductor 28 the coil of interlock relay 4 conductor 7 29, contact members 0 on relay 38, conductor 30 and safety devices, to line conductor L The energization of interlock relay 4 closes its contact members Z) to complete a circuit for the up-direction switch 1 as follows: from line conductor L through conductor 24, contact members (Z of relay 38, conductors 32 and 33, contact members 6 of interlock relay 4, contact members a of interlock relay 5, the operating coil of up-direction switch 1 and thence, through the safety devices,to line conductor L Up-direction switch 1 closes connecting the generator field winding GF to line in series with resistors 1", and 1' through a circuit as follows: from line conductor L through resistors 1' and 9",, contact members a of updirection switch 1, the generator field winding GF and contact members 7) of up-direction switch 1, to line conductor L U p-direction switch 1, in closing, also energizes the release coil of brake B through a circuit as follows: from line conductor L through the release coil. of brake B, through contact members 0 of Lip-direction switch 1, to line conductor L Contact members d of lip-direction switch 1 also prepare the circuit of the coils of inductor relays 6 and 8 for subsequent closure upon centering of the car switch C8.

The reversing switch 1, in closing, also establishes a holding circuit for itself as follows: from line conductor L through conductor 24, contact members (Z of relay 38, Contact members of push button PB, contact members of inductor relay 8, contact members 6 of reversing switch 1, contact members a of interlock relay 5, the operating coil of reversing switch 1 and thence, through the safety devices, to line conductor L The generator- G now generates a low voltage, the brake B is released and the car moves upward at slow speed.

If the handle of car switch Cs is moved farther in a counter-clockwise direction, contact segment 25 engages contact member 31,

closing the circuit of accelerating relay 3 as follows: from line L through contact member 26, contact segment 25 and contact member 31 of the car switch Cs, the operating coil of accelerating relay 3 and thence, through the safety devices, to line conductor L Accelerating relay 3 closes to establish a holding circuit for itself as follows: from line conductor L through contact members of the inductor relays 6 and 7, through contact members a of accelerating relay 3, through the operating coil of accelerating relay 3, through the safety devices, to line conductor L The closure of accelerating relay 3 short circuits resistor 1' to increase the generator excitation and cause the car tooperate at full speed.

The handle of car switch Cs is held to the left as the car passes the second floor, the

inductor plates 6', 7 and 8 for the second a floor having no effect on the inductor relays 6, 7 and 8, as the coils of the latter are deenergized.

At some time before the inductor relays 6,

7 and 8 reach the inductor plates 6, 7 and 8 for the third floor, the car switch Cs is centered. When this occurs, the closing circuit of accelerating relay 3 is broken at contact member 31 of the car switch, but the accelerating relay 3 remains energized through its holding circuit. The circuit of interlock relay 4 is broken at contactmember 27 of the car switch, and the interlock relay drops out. However, the reversing switch 1 remains energized through its holding circuit described above. Centering of the car switch also completes an energizing circuit for the inductor relays 6 and 8 as follows: from line conductor L through contact member 26, contact segment 25 and contact member 34 of the car switch Cs, through the coils of inductor relays 8 and 6 and contact members (Z of reversing switch 1, to line conductor L The inductor relays 6 and 8 donot immediately open their contact members, as their magnetic circuits are still incomplete.

When the inductor relay 6 arrives at a position opposite its inductor plate 6 for the third floor, the relay opens, opening its Contact members and breaking the holding circuit of accelerating relay 3. Accelerating relay 3 drops out to insert the resistor T in series with the generator field winding GF and thus reduce the generator excitation and the speed of the car to its low-speed value.

The car continues to move upward at low speed until the inductor relay 8 arrives at a position opposite its inductor plate 8 for the third floor. When this occurs, the magnetic circuit of the relay 8 is completed, and the relay opens its contacts to break the holding circuit of reversing switch 1. Reversing switch 1 drops out, breaking the circuit of the generator field winding GF at its contact members a and b and breaking the circuit of the coil of inductor relays 6 and 8 at its contact members cl. The inductor relays close their contacts in preparation for further operation. The opening of reversing switch 1 also breaks the circuit of the release coil of the brake B so that the brake is applied and the car brought to rest.

The car is now at rest at the third floor, all doors and gates are closed, the relays 38, 39L and 39B are all energized, the anti-creep ing switches LU, LD, EU and RD are all retired, the car switch C8 is centered, and the reversing switches 1 and 2, accelerating relay 3 and interlock relays 4c and 5 are all deenergized. Anti-creeping switches LU and LD may be put into operation to maintain the left end of the car platform level with the floor by opening a left gate or door; anticreeping switches RU and RD may be put into operation to maintain the right end of the car platform level with the floor by opening a right gate or door; or operation of the car in either direction to another landing may be initiated by the car switch Cs.

Operation of the car in the down direction will be readily understood from the above description of operation in the up direction.

It will be understood that my invention consists in providing means for maintaining the car platform level with the floor at the side at which a door or gate is first opened. I/Vhile I have shown my invention applied to a system in which the motive means is a Ward- Leonard system, I contemplate the use of any other suitable driving means. My invention is furthermore not limited to a two-speed elevator system or to a manually started and automatically stopped system but may be applied to any of the usual elevator systems.

I do not wish to be restricted to the specific structural details, arrangement of parts or circuit connections herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of my invention. I desire therefore, that only such limitations shall be imposed as are indicated in the appended claims.

By the terms door in the appended claims I mean any removable barrier between the elevator platform and a landing, whether carried by the car or mounted on the landing.

I claim as my invention:

1. In an elevator system, an elevator platform, means for moving said platform to a landing, a door for a first side of said platform, a door for a second side of said platform, levelling means for maintaining said first side of said platform level with the landing, levelling means for maintaining said second side of said platform level with the landing and means responsive to the opening of a door for initiating operation of one of said levelling means and for preventing operation of the other of said levelling means.

2. In an elevator system, .an elevator platform, means for movmg sa1d platform to a landing, a door for a first side of said platoperation of thelevelling means for the side .of the platform corresponding to sa1d opened door and for preventing operation of the other of said levelling means.

3. In an elevator system, an elevator platform, means for moving said platform to a la; ling, door for a first side of said platform, a door for a second side of saidplatform, levelling means for said first side of said platform, levelling means for said-second side of said platform, means responsive to the closure of both doors for preventing operation of either of said. levelling means, and means responsive to the opening of a door after both doors have been closed for initiating operation of the levelling means for the side of the platform corresponding to said opened door and for preventing operation of the other of said levelling means.

I. In an elevator system, an elevator platform, means for moving said platform to a landing, a door for a first side of said plat form, a door for a second side of said platform, levelling means for said first side of said platform including a cam-operated switch and cam for operating said switch, levelling means for said second side of said platform including a second cam-operated switch and a cam for operating said switch, means responsive to the closure of both doors for preventing operation of either of said levelling means, and means responsive to the opening of a door after both doors have been closed for initiating operation of the levelling means for the side of the platform corresponding to said opened door and for preventing operation of the other of said levelling means.

5. In an elevator system, an elevator platform, means for moving said platform to a landing, a door for a first side of said platform, a door for a second side of said platform, levelling means for said first side of said platform including a cam-operated switch and a cam for operating said switch, electromagnetic means for separating said switch and said cam, levelling means for said second side of said platform including a second cam-operated switch and a second cam for operating said switch, electromagnetic means for separating said second switch and said second cam, means responsive to the closure of both of said doors for preventing operation of either of said levelling means including means for energizing both of said electromagnetic means, and means responsive to the opening of a door after both of said doors have been closed for initiating operation of the levelling means for the side of said platform corresponding to the opened door and for preventing operation of the other of said levelling means.

6. In an elevator system, an elevator platform, means for moving said platform to a landing, a first door for a first side of said platform, a second door for a second side of 0 said platform, a first levelling means for said first side of said platform, a second levelling means for said second side of said platform, means responsive to the opening of said first door for initiating operation of said first levelling means and for preventing the operation of said second levelling means, and means responsive to the closure of said first door, when said second door is open, for initiating operation of said second levelling I 20 means and for preventing operation of said first levelling means.

7 In an elevator system, an elevator platform having first and second sides, means for moving said platform to a landing, leveling -LI mechanism for said first side of said platform, additional leveling mechanism for said second side of said platform, and selectively operable means for initiating operation of either of said leveling mechanisms, said selectively operable means including means to prevent simultaneous operation of both of said leveling mechanisms.

In testimony whereof, I have hereunto subscribed my name this 20th day of January,

WILLIAM R. DAVIS. 

